The History of ICF Foam Blocks

Contrary to many poorly-researched articles regarding the history of ICF Foam Blocks which credit their invention to the 1960’s, or others that state that Insulating concrete forms made from a mixture of treated wood fibers and Portland cement were invented in Switzerland soon after World War II, Durisol, as the first ICF block was known, was actually developed in Belgium in 1937 by the Swiss nationals August Schnell and Alex Bosshard (following on from a Dutch patent registered in 1932.) At the time, they made little impact on the construction industry but in 1938, these two men founded Durisol AG für Leichtbaustoffe in Dietikon near Zurich, Switzerland, to push this ICF’s industrial development and allowed the company to break into international markets, including the Netherlands, France, and Belgium after World War II – filling the void for a quick, cost effective and solid construction method using largely unskilled labor. Subsequent International patents followed including (According to The Canadian Patent Office Record and Register Volume 81, Issues 4-6 May 19th 1953) – Swiss Patent Application Nov 4th, 1949 Serial Number 593,899 In CH Nov 6th, 1948 and subsequently Canadian Patent 492,991 of the same date. By 1959, as reported in Barron’s National Business and Financial Weekly, Volume 39, Durisol was promoted as cutting traditional construction costs by 20-30% and was already produced in 13 countries! Durisol today operates worldwide as a manufacturer of cement-bonded wood fibre products, with 14 manufacturing locations throughout the world and therefore take the crown for having invented ICFs and being used in construction worldwide for over 80 years.

In detail, for the eternally curious, polystyrene was discovered in 1839 by Eduard Simon a pharmacist based in Berlin, who distilled benzoin or copalm balsam, the correct name for the resin of the American sweetgum tree (Liquidambar styraciflua) into an oily substance, a monomer that he named styrol as he referred to the resin mistakenly by the name storax (a bastardisation of the trees genus name of styrax). Several days later, Simon found that his styrol had thickened into a gel he then mistakenly called styrol oxide (“Styroloxyd”) because he presumed oxidation had taken place. In 1845 Jamaican-born chemist John Buddle Blyth and German chemist August Wilhelm von Hofmann demonstrated the transformation of styrol to a gel in the absence of oxygen and they christened this “metastyrol.” Subsequent chemical analysis demonstrated that this was identical to Simon’s Styroloxyd and in 1866 Marcelin Berthelot correctly identified the formation of metastyrol/Styroloxyd from styrol as a process of polymerisation. Around 1946 it was realized that heating styrol starts a chain reaction producing macromolecules as contained in the thesis of German organic chemist Hermann Staudinger (1881–1965). This ultimately led to the hard clear substance produced receiving its present name of polystyrene – although most people associate the name polystyrene with what is actually and more accurately described as EPS foam.

Somewhat confusingly, according to the book authored by Fritz Störi entitled “The Stuff Foams Are Made of – The History of Styropor”. Polystyrene, the plasticized material derived from Styrene (which whilst this is classified as a “plastic” could as seen above be of plant origin), was invented in 1930 – but BASF Expandable Polystyrene (EPS) foam (Styropor®) was invented by accident by a BASF scientist Fritz Stastny in 1949 when he was experimenting the process of using steam to expand beads and the possible commercial applications for polystyrene in general as a potential insulator for telephone cables. He left a sample of clear polystyrene in the baking oven in a shoe-polish tin, only to find after several hours what he described as “a veritable foam monster” which appeared “over the course of the next 36 hours. Like a beret, the lid of the can was perched right on top of a 10-inch-thick chunk of foam!” BASF perfected the molding process for their new plastic foam, patented it in 1952, and BASF introduced its new product Styropor® EPS to the public for the first time in 1952, at the plastics trade fair in Düsseldorf, Germany molded using steam right on the exhibition stand into the form of “the world’s lightest toy ship”. Ever since, EPS has been one of the most widely used thermal insulations in the world and is applied ever increasingly in architecturally designed, energy-efficient buildings. Its low cost, versatility and high R-value per dollar make EPS insulation the preferred product of architects, specifiers and application contractors across the country and its recyclability, chemical stability and environmental sustainability (being 98% air) is a bonus.